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diff --git a/html/quick.htm b/html/quick.htm new file mode 100644 index 000000000000..4eecf8241854 --- /dev/null +++ b/html/quick.htm @@ -0,0 +1,100 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"> +<html> +<head> +<meta name="generator" content="HTML Tidy, see www.w3.org"> +<title>Quick Start</title> +</head> +<body> +<h3>Quick Start</h3> + +<img align="left" src="pic/panda.gif" alt="gif">FAX test image for +SATNET (1979). + +<p>The baby panda was scanned at University College London and used +as a FAX test image for a demonstration of the DARPA Atlantic +SATNET Program and the first transatlantic Internet connection in +1978. The computing system used for that demonstration was called +the <a href= +"http://www.eecis.udel.edu/~mills/database/papers/fuzz.ps"> +Fuzzball</a> . As it happened, this was also the first Internet +multimedia presentation and the first to use NTP in regular +operation. The image was widely copied and used for testing purpose +throughout much of the 1980s.<br clear="left"> +</p> + +<hr> +<p>For the rank amateur the sheer volume of the documentation +collection must be intimidating. However, it doesn't take much to +fly the <tt>ntpd</tt> daemon with a simple configuration where a +workstation needs to synchronize to some server elsewhere in the +Internet. The first thing that needs to be done is to build the +distribution for the particular workstation and install in the +usual place. The <a href="build.htm">Building and Installing the +Distribution</a> page describes how to do this.</p> + +<p>While it is possible that certain configurations do not need a +configuration file, most do require one. Strictly speaking, the +file need only contain one line specifying a remote server, for +instance</p> + +<p><tt>server foo.bar.com</tt></p> + +<p>Choosing an appropriate remote server is somewhat of a black +art, but a suboptimal choice is seldom a problem. Links to public +time servers operated by National Institutes of Science and +Technology (NIST), US Naval Observatory (USNO), Canadian Metrology +Centre (CMC) and many others are given in the home page of this +document collection. The lists are sorted by country and, in the +case of the US, by state. Usually, the best choice is the nearest +in geographical terms, but the terms of engagement specified in +each list entry should be carefully respected.</p> + +<p>During operation <tt>ntpd</tt> measures and corrects for +incidental clock frequency error and writes the current value to a +file if enabled. If the <tt>ntpd</tt> is stopped and restarted, it +initializes the frequency from this file. In this way the +potentially lengthy interval to relearn the frequency error is +avoided. Thus, for most applications an additional line should be +added to the file of the form</p> + +<p><tt>driftfile /etc/ntp.drift</tt></p> + +<p>That's all there is to it, unless some problem in network +connectivity or local operating system configuration occurs. The +most common problem is some firewall between the workstation and +server. System administrators should understand NTP uses UDP port +123 as both the source and destination port and that NTP does not +involve any operating system interaction other than to set the +system clock. While almost all modern Unix systems have included +NTP and UDP port 123 defined in the services file, this should be +checked if <tt>ntpd</tt> fails to come up at all.</p> + +<p>The best way to confirm NTP is working is using the <a href= +"ntpq.htm"><tt>ntpq</tt></a> utility, although the <a href= +"ntpdc.htm"><tt>ntpdc</tt></a> utility may be useful in extreme +cases. See the documentation pages for further information. In the +most extreme cases the <tt>-d</tt> option on the <tt>ntpd</tt> +command line results in a blow-by-blow trace of the daemon +operations. While the trace output can be cryptic, to say the +least, it gives a general idea of what the program is doing and, in +particular, details the arriving and departing packets and detected +errors, if present.</p> + +<p>Sometimes the <tt>ntpd</tt>. behavior may seem to violate the +Principle of Least Astonishment, but there are good reasons for +this. See the <a href="ntpd.htm">Network Time Protocol (NTP) +daemon</a> page for revealing insights. See this page and its +dependencies for additional configuration and control options. The +<a href="notes.htm">Notes on Configuring NTP and Setting up a NTP +Subnet</a> page contains an extended discussion of these +options.</p> + +<hr> +<a href="index.htm"><img align="left" src="pic/home.gif" alt= +"gif"></a> + +<address><a href="mailto:mills@udel.edu">David L. Mills +<mills@udel.edu></a></address> +</body> +</html> + |